HPTLC Method for Determination of R, R-Glycopyrronium Bromide and its Related Impurities.

An innovative high-performance thin layer chromatographic (HPTLC) method was designed, optimized and validated for the quantification of R, R-glycopyrronium bromide (GLY) and its related impurities in drug substance and drug product. Separation was performed on HPTLC plates pre-coated with silica gel 60 F254 by dichloromethane:methanol:formic acid (10:0.5:0.5, v/v/v) as a developing system. GLY and its related impurities namely, glycopyrronium impurity G and glycopyrronium impurity J, were separated giving compact well-resolved spots with significant retardation factor (Rf) values of 0.17 ± 0.02, 0.34 ± 0.02 and 0.69 ± 0.02, respectively. Quantification was done at 220 nm in the ranges of 0.3-10 and 0.2-4.0 μg/spot with limits of detection and quantification of 0.1, 0.3 and 0.05, 0.2 μg/spot for GLY and its related impurities, respectively. Good accuracy was obtained with mean percentage recovery of 99.48 ± 1.36, 100.04 ± 1.32 and 99.61 ± 0.80 and R2 ≥ 0.9968 for GLY and its impurities, consecutively. Validation parameters were presented according to the International Conference on Harmonization. The method was used to investigate impurity profile of GLY in drug substance and drug product and could be applied in routine analysis of the drug. Comparison between the developed method and the reported method revealed no statistical difference.